Numerical investigation of Reynolds number effects on vortex-induced vibrations at low and moderate Re regimes

Reynolds number effects on vortex-induced vibration are paid more and more attention, as the reliability and efficiency of risers, pipelines and cables becoming crucial to the performance of production system installed in deep water. Since its strong nonlinearities and correlations to multi-factors on both structure and fluid characteristics, Re effects are still far to be fully understood. In the present article, numerical studies are implemented on an elastically mounted circular cylinder at low and moderate Re regimes (Re = 100-1650, 1700-27000) respectively, under the circumstances of low mass-damping. Re effects are investigated extensively on the response amplitude, frequency, drag, lift coefficient and also vortex-shedding patterns. In overall, Re effects are found more prominent at the moderate Re than that at the low Re regime. Specifically, the significant response amplitudes are found more sensitive to the Re variation than the significant frequency and hydrodynamic coefficients at both Re regimes. The peak amplitude and synchronization region are revealed to increase with the increase of Re at the moderate regime. In addition, the effectiveness of alpha is further validated in characterizing the correlation between Re and U* among different oscillatory systems.

Automated summary

In this article, numerical studies were conducted to investigate the effects of Reynolds number on vortex-induced vibration. The results showed that Reynolds number had more significant effects at moderate Reynolds numbers. The response amplitude was more sensitive to Reynolds number variations, while the frequency and hydrodynamic coefficients showed less variation. Additionally, the effectiveness of alpha in characterizing the correlation between Reynolds number and U* in different oscillatory systems was validated.